Clarithromycin is an investigational macrolide antibiotic with in vitro activity against Mycobacterium avium-intracellulare (MAI) and Toxoplasma gondii. This activity makes it an attractive agent for investigation in patients with HIV infection who are prone to opportunistic infections with these organisms. This study evaluates the tolerance of clarithromycin with AZT and determine a MTD in combination with AZT.